To destroy a specific target of a defined armor protection and size, a given fragmentation warhead must deliver a large number of optimally sized fragments within an effective lethal area. To combat multiple threat scenarios, the U.S. military must maintain supplies of several different fragmentation warheads, each type adapted for use against a particular target set. This obligatory approach creates a burden on logistics and supply. Additionally, existing artillery and mortars produce limited lethality depending upon the grade of steel used in their shells. Making more lethal, multi-purpose munitions available to the military would result in significant inventory reductions and cost savings.
The U.S. military employs fragmentation warheads against a wide variety of targets ranging from personnel, radar systems, trucks, parked aircraft, and rocket launchers to armored personnel carriers .and self-propelled artillery. One significant obstacle to mission success is that a fragmentation warhead designed to defeat personnel is not generally effective against materiel targets including trucks and light armored vehicles, where fragments of relatively greater size and mass are required. As mentioned, military units must maintain supplies of several different fragmentation warheads, each type adapted for use against a particular type of target. This results in a burden on logistics and supply.
Existing artillery and mortars produce limited lethality depending upon the grade of steel used in their shells. Warhead designers have tried several techniques to enhance fragmentation including: using harder High Fragmentation (HF) steel in the shell body, scoring the shell body, adding preformed fragments, and applying multiple detonator initiation schemes. While these techniques can improve lethality, each traditional approach presents its own problems. Manufacturing HF steel involves a time consuming and costly heat treatment process. Scoring the casing weakens the shell's structural rigidity presenting potential problems related to survivability. Specifically, the scored grooves act as stress concentration points during the set back stage of gun launch. Adding preformed fragments helps to assure that the warhead delivers a few optimally sized fragments but fails to enhance the fragmentation of the existing shell casing. Multiple detonator initiation schemes are very complicated and the additional detonators reduce the amount of space available for high explosive material.
To effectively engage multiple target types, the U.S. military requires an easily producible, multi-mode warhead alternative at a reasonable cost. Described here to meet this challenge is a high performance variable lethality, multi-purpose warhead using a novel adaptive fragmentation mechanism. The invention enables the modern warfighter to instantaneously modify a fragmentation warhead in the field, generating a desired fragment size to neutralize a broad range of targets, from personnel targets to light armored vehicles. Additionally, adaptive fragmentation can minimize collateral damage by focusing the warhead's lethal effects upon the intended targets.
This invention can increase lethality by fitting conventional fragmentation warheads with inexpensive, dynamically configurable patterned insert sleeve mechanisms, to control the fragment mass distribution.